Vehicle communication apparatus and vehicle

ABSTRACT

A vehicle communication apparatus includes a plurality of remote units (RUs) configured to transmit signals to a mobile communication network and to receive signals from the mobile communication network, and a central unit (CU) configured to provide data based on the signals received through the plurality of remote units to one or more devices located in a vehicle. The plurality of remote units includes an array antenna attached to a body of the vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 16/329,884, filed on Mar. 1, 2019, which is a National Stage application under 35 U.S.C. § 371 of International Application No. PCT/KR2017/007974, filed on Jul. 25, 2017, which claims the benefit of U.S. Provisional Application No. 62/367,769, filed on Jul. 28, 2016. The disclosures of the prior applications are incorporated by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a vehicle communication apparatus and a vehicle.

BACKGROUND ART

A vehicle refers to an apparatus moved by a user in a desired direction and representative examples thereof include automobiles.

As the frequency of use of wireless communication of a passenger in a vehicle increases and the number of categories of services using wireless communication increases, it is necessary to provide a high data rate and high quality of service (QoS) to users at a high speed unlike the related art.

For example, when a plurality of users using public transportation wants to view multimedia content or a plurality of passengers in a private vehicle traveling on a highway uses different mobile communication systems, a mobile communication system needs to provide good wireless services to the users.

According to such necessity, an array antenna having a large size is required. However, due to the aerodynamic structure and exterior design of a vehicle, it is difficult to attach a large array antenna to the vehicle.

DISCLOSURE Technical Problem

Accordingly, an object of the present invention is to provide a communication apparatus capable of providing good wireless services.

In addition, another object of the present invention is to provide a vehicle including the communication apparatus.

The technical problems solved by the present invention are not limited to the above technical problems and other technical problems which are not described herein will become apparent to those skilled in the art from the following description.

Technical Solution

According to an aspect of the present invention, a vehicle communication apparatus includes a plurality of remote units (RUs) configured to transmit signals to a mobile communication network and to receive signals from the mobile communication network, and a central unit (CU) configured to provide data based on the signals received through the plurality of remote units to one or more devices located in a vehicle. The plurality of remote units includes an array antenna attached to a body of the vehicle.

The details of other embodiments are included in the detailed description and drawings.

Advantageous Effects

The embodiments of the present invention include one or more of the following effects.

First, it is possible to prevent communication performance deterioration due to penetration loss having an average value of about 20 dB.

Second, it is possible to obtain large array again by using a larger number of antennas than a personal portable communication device.

Third, it is easy to secure a distance between antennas and to secure diversity.

Fourth, it is possible to provide an excellent communication service as compared to a personal portable device without additional investment in infrastructure.

The effects of the present invention are not limited to the above-described effects and other effects which are not described herein may be derived by those skilled in the art from the following description of the embodiments of the present invention.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view referenced to describe a communication apparatus provided in a vehicle according to an embodiment of the present invention.

FIGS. 2 to 4 are views referenced to describe a vehicle communication apparatus according to an embodiment of the present invention.

FIG. 5 is a view referenced to describe a vehicle communication apparatus according to an embodiment of the present invention.

FIG. 6 is a detailed block diagram of FIG. 5.

FIGS. 7 to 8 are views referenced to describe a vehicle communication apparatus according to an embodiment of the present invention.

FIG. 9 is a view referenced to describe a plurality of array antennas according to an embodiment of the present invention.

FIG. 10 illustrates addition of an AGC/AFC controller block to a remote radio head (RRH) according to an example or implementation example of the present invention.

FIG. 11 illustrates the addition of IF function block between an RFIC and a modem.

FIG. 12 illustrates a reference model having a 3-step function block of RFIC, modem and AP.

BEST MODE

Exemplary embodiments of the present invention will be described below in detail reference to the accompanying drawings in which the same reference numbers are used throughout this specification to refer to the same or like parts and a repeated description thereof will be omitted. The suffixes “module” and “unit” of elements herein are used for convenience of description and thus can be used interchangeably and do not have any distinguishable meanings or functions. In describing the present invention, a detailed description of known functions and configurations will be omitted when it may obscure the subject matter of the present invention. The accompanying drawings are used to help easily understood the technical idea of the present invention and it should be understood that the idea of the present invention is not limited by the accompanying drawings. The idea of the present invention should be construed to extend to any alterations, equivalents and substitutions besides the accompanying drawings.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements of the present invention, these terms are only used to distinguish one element from another element and essential, order, or sequence of corresponding elements are not limited by these terms.

It will be understood that when one element is referred to as being “connected to” or “coupled to” another element, one element may be “connected to” or “coupled to”, another element via a further element although one element may be directly connected to or directly accessed to another element.

A singular representation may include a plural representation unless the context clearly indicates otherwise.

It will be understood that the terms ‘comprise’, ‘include’, etc., when used in this specification, specify the presence of several components or several steps and part of the components or steps may not be included or additional components or steps may further be included.

A vehicle as described in this specification may include an automobile and a motorcycle. Hereinafter, an automobile will be focused upon.

A vehicle as described in this specification may include all of a vehicle including an engine as a power source, a hybrid vehicle including both an engine and an electric motor as a power source, and an electric vehicle including an electric motor as a power source.

In the following description, the left of a vehicle means the left of a driving direction of the vehicle, and the right of the vehicle means the right of the driving direction of the vehicle.

FIG. 1 is a view referenced to describe a communication apparatus provided in a vehicle according to an embodiment of the present invention.

Referring to FIG. 1, the vehicle communication apparatus 10 may include a plurality of remote units (RUs) 100 and a central unit (CU) 200.

The plurality of remote units 100 may be connected to the central unit 200 by wire.

The plurality of remote units 100 may be wirelessly connected to the central unit 200.

The plurality of remote units 100 may be connected to a mobile communication network.

The plurality of remote units 100 may transmit signals to the mobile communication network.

The plurality of remote units 100 may transmit signals to an external device through the mobile communication network. Here, the external device may include at least one of a mobile terminal, a vehicle or a server, which is outside the vehicle.

The plurality of remote units 100 may receive signals from the mobile communication network.

The plurality of remote units 100 may receive signals from the external device through the mobile communication network. Here, the external device may include at least one of a mobile terminal, a vehicle or a server, which is outside the vehicle.

Each of the plurality of remote units 100 may include an array antenna.

The array antenna may be attached to a vehicle body.

The plurality of array antennas may be distributed and disposed on the upper end of the vehicle body.

For example, the array antennas may be distributed and attached to at least one of a hood, a roof, a trunk, a front windshield, a rear windshield or a side mirror.

For example, the array antennas may be attached to at least one of a hood, a roof, a trunk, a front windshield, a rear windshield or a side mirror to face the sky.

For example, the array antennas may be attached to at least one of a hood, a roof, a trunk, a front windshield, a rear windshield or a side mirror to face a side opposite to the ground.

When the array antenna is located at the upper end of the vehicle body, transmission/reception power performance is excellent.

By the plurality of array antennas respectively included in the plurality of remote units 100, it is possible to implement a multiple input multiple output (MIMO) system.

If such a MIMO system is implemented, communication capacity (e.g., communication data capacity) increases.

The plurality of remote units 100 may include a first remote unit 100 a, a second remote unit 100 b, a third remote unit 100 c and a fourth remote unit 100 c.

In some embodiments, the plurality of remote units 100 may include two, three or five remote units.

Meanwhile, the plurality of remote units 100 may receive received signals from the same external device through different frequency bands.

For example, the plurality of remote units 100 may include a first remote unit 100 a and a second remote unit 100 b. The first remote unit 100 a may receive a received signal from a first server through a first frequency band. The second remote unit 100 b may receive a received signal from the first server through a second frequency band.

Meanwhile, the plurality of remote units 100 may receive received signals from the same external device through different time bands.

For example, the plurality of remote units 100 may include a first remote unit 100 a and a second remote unit 100 b. The first remote unit 100 a may receive a received signal from the first server through a first time band. The second remote unit 100 b may receive a received signal from the first server through a second time band.

The central unit 200 may collectively control the plurality of remote units 100.

The central unit 200 may control each of the plurality of remote units 100.

The central unit 200 may be connected to the plurality of remote units 100 by wire.

The central unit 200 may be wirelessly connected to the plurality of remote units 100.

The central unit 200 may provide data based on the received signals received through the plurality of remote units 100 to one or more devices located in the vehicle.

For example, the central unit 200 may provide data based on the signals received through the plurality of remote units 100 to mobile terminals carried by one or more passengers.

The device located in the vehicle may be a mobile terminal located in the vehicle and carried by the passenger.

The device located in the vehicle may be a user interface device provided in the vehicle.

The user interface device is used to communicate between a vehicle and a user. The user interface device may receive user input and provide information generated by the vehicle to the user. The vehicle 100 may implement a user interface (UI) or user experience (UX) through the user interface device.

The user interface device includes a navigation device, an audio video navigation (AVN) device, a center integrated display (CID), a head up display (HUD), etc.

FIGS. 2 to 4 are views referenced to describe a vehicle communication apparatus according to an embodiment of the present invention.

The plurality of remote units 100 and the central unit 200 will be described with reference to FIGS. 2 to 4.

By appropriately distributing and allocating function/layer modules to the remote units 100 and the central unit 200, it is possible to reduce RF implementation difficulty and to obtain implementation gain such as solution of cabling issues between the remote units 100 and the central unit 200.

Referring to FIGS. 2 to 4, each of the plurality of remote units 100 may include a radio frequency (RF) module 110.

The RF module 110 may include an array antenna 111 and an RF circuit capable of implementing a communication protocol.

The array antenna 111 may function as a transmission antenna and a reception antenna.

The RF module 110 may include at least one phase locked loop (PLL) circuit and at least one amplifier.

The PLL circuit may include an oscillator.

The RF module 110 may further include at least one mixer, at least one filter and a combination thereof.

The RF module 110 may be controlled by a first modem or a second modem.

Alternatively, the RF module 110 may be controlled by processors, that is, a first processor or a second processor.

The central unit 200 may include an access point (AP) 210.

The access point 210 may be connected to the plurality of remote units 100 and one or more devices 310, 320 and 330 located in the vehicle.

The access point 200 may provide data based on the received signals received through the plurality of remote units 100 to one or more devices located in the vehicle.

Meanwhile, the access point 200 and the modem 120 may exchange signals, information or data through a digital interface.

Referring to FIG. 2, each of the plurality of remote units 100 may include the RF module 110 and the first modem 120.

The above description is applicable to the RF module 110.

The first modem 120 may be implemented at L1 (Layer 1, e.g., a physical layer), L2 (Layer 2, e.g., a MAC layer), a radio resource control (RRC) layer, or a non-access stratum (NAS) layer.

The first modem 120 may perform phase locked loop (PLL) control. For example, the first modem 120 may perform phase locked loop control through automatic frequency compensation control.

Phase clocked loop control means that the RF module 110 is controlled in order to constantly maintain the frequency of an output signal.

The first modem 120 may perform automatic gain control.

Automatic gain control means that gain is controlled such that output is constant even when input is changed in the RF module 110.

The first modem 120 may calculate an automatic gain control value.

The first modem 120 may control the amplifier of the RF module 110 based on the automatic gain control value.

For example, the first modem 120 may measure a received signal strength indicator (RSSI) of the RF module 110. The first modem 120 may calculate the automatic gain control value based on the measured RSSI data.

The first modem 120 may perform automatic frequency compensation control.

Automatic frequency compensation control means that the PLL circuit included in the RF module 110 is controlled based on a voltage according to a signal period and an oscillation period difference.

The first modem 120 may calculate an automatic frequency compensation control value.

The first modem 120 may control the PLL circuit of the RF module 110 based on the automatic frequency compensation control value.

For example, the first modem 120 may perform synchronization of the RF module 110.

The first modem 120 may calculate the automatic frequency compensation control value based on synchronization data.

The first modem 120 may modulate a signal transmitted through the RF module 110.

The first modem 120 may demodulate a signal received through the RF module 110.

The central unit 200 may include the access point 210.

The above description is applicable to the access point 210.

Meanwhile, in new radio (NR), as communication using a high frequency band such as an mmWave band has been discussed, necessity of a 2-step transceiver for converting a baseband signal into a high frequency band through an intermediate frequency (IF) band is emerging, instead of a transceiver for directly converting a baseband signal into a high frequency band. For example, in communication using an mmWave frequency band (e.g., 28 GHz), operation of converting the baseband signal into the IF band (e.g., 8 to 10 GHz) in a first transceiver and converting the IF band into the mmWave band (e.g., 28 GHz) in a second transceiver may be performed.

Based on signal flow, an IF unit may be further included between the RF module 110 and the first modem 120.

The IF unit may be included in the remote unit 100.

The IF unit may perform frequency band conversion.

The RF module 110 may convert the frequency band.

If the IF unit is further included, the RF module 110 may convert the IF band (e.g., 8 to 10 GHz) into the mmWave band (e.g., 28 GHz) or convert the mmWave band into the IF band.

The IF unit may convert the baseband into the IF band (e.g., 8 to 10 GHz) or convert the IF band into the baseband.

The IF unit may further include a local oscillator and an IF PLL circuit.

Referring to FIG. 3, each of the plurality of remote units 100 may include an RF module 110 and the first modem 121.

The above description is applicable to the RF module 110.

The first modem 121 may be implemented at L1 (Layer 1, e.g., a physical layer).

The first modem 121 may perform phase locked loop (PLL) control. For example, the first modem 121 may perform phase locked loop control through automatic frequency compensation control.

The first modem 121 may calculate an automatic gain control value.

The first modem 121 may control the amplifier of the RF module 110 based on the automatic gain control value.

The first modem 121 may calculate an automatic frequency compensation control value.

The first modem 121 may control the PLL circuit of the RF module 110 based on the automatic frequency compensation control value.

The central unit 200 may include a second modem 205 and an access point 210.

The second modem 205 may be implemented at L1 (Layer 1, e.g., a physical layer), L2 (Layer 2, e.g., a MAC layer), a radio resource control (RRC) layer, or a non-access stratum (NAS) layer.

The second modem 205 may modulate a signal transmitted through the RF module 110.

The second modem 205 may demodulate a signal received through the RF module 110.

The second modem 205 may measure a received signal strength indicator (RSSI) of the RF module 110.

The second modem 205 may provide the measured RSSI data to the first modem 121. The first modem 121 may calculate an automatic gain control value based on the measured RSSI data.

The second modem 205 may perform synchronization of the RF module 110.

The second modem 205 may provide synchronization data to the first modem 121. The first modem 120 may calculate an automatic frequency compensation control value based on the synchronization data.

The above description is applicable to the access point 210.

Meanwhile, an IF unit may be further included between the RF module 110 and the first modem 121.

The description of FIG. 2 is applicable to the RF module 110 and IF unit.

Referring to FIG. 4, each of the plurality of remote units 100 may include an RF module 110 and a converter 130.

The above description is applicable to the RF module 110.

The converter 130 may interconvert an analog signal and a digital signal.

The converter 130 may include an analog-to-digital converter (ADC) for converting an analog signal into a digital signal and a digital-to-analog converter (DAC) for converting a digital signal into an analog signal.

The central unit 200 may include a processor 206, a second modem 206 and an access point 210.

The processor 206 may be referred to as an antenna signal processor or a multiple AGC & AFC controller.

The processor 206 may collectively control the plurality of remote units 100.

The processor 206 may collectively control the PLL circuit and amplifier of each of the plurality of remote units 100.

The processor 206 may perform phase locked loop (PLL) control. For example, the processor 206 may perform phase locked loop control through automatic frequency compensation control.

The processor 206 may calculate an automatic gain control value.

The processor 206 may calculate the automatic gain control value based on a remote unit having best gain among the plurality of remote units 100.

The processor 206 may calculate the automatic gain control value based on average received power of the plurality of remote units 100.

The processor 206 may control the amplifier of the RF module 110 based on the automatic gain control value.

The processor 206 may calculate an automatic frequency compensation control value.

The processor 206 may control the PLL circuit of the RF module 110 based on the automatic frequency compensation control value.

The second modem 206 may be implemented at L1 (Layer 1, e.g., a physical layer), L2 (Layer 2, e.g., a MAC layer), a radio resource control (RRC) layer, or a non-access stratum (NAS) layer.

The second modem 206 may measure a received signal strength indicator (RSSI) of the RF module 110. The second modem 206 may provide the measured RSSI data to the processor 201. The processor 201 may calculate an automatic gain control value based on the RSSI data.

The second modem 206 may perform synchronization of the RF module 110. The second modem 206 may provide synchronization data to the processor 201. The processor 201 may calculate an automatic frequency compensation control value based on the synchronization data.

The second modem 206 may modulate a signal transmitted through the RF module 110.

The second modem 206 may demodulate a signal received through the RF module 110.

The above description is applicable to the access point 210.

Meanwhile, an IF unit may be further included between the RF module 110 and the second modem 206.

The IF unit may be included in the remote unit 100.

For example, the IF unit may be disposed between the RF module 110 and the converter 130, based on signal flow.

For example, the IF unit may be disposed after the converter 130, based on signal flow.

The IF unit may be included in the central unit 200.

The IF unit may be disposed before the processor 201, based on signal flow.

The IF unit may be disposed between the processor 201 and the modem 206, based on signal flow.

The description of FIG. 2 is applicable to the RF module 110 and the IF unit.

FIG. 5 is a view referenced to describe a vehicle communication apparatus according to an embodiment of the present invention.

FIG. 6 is a detailed block diagram of FIG. 5.

The description of the RF module 110 of FIG. 6 is applicable to the RF modules 110 of FIGS. 2 to 5.

Referring to FIGS. 5 to 6, each of the plurality of remote units 100 may include an RF module 110 and a converter 130.

The RF module 110 may include at least one phase locked loop (PLL) circuit 520 and at least one amplifier 510 a, 510 b and 510 c.

The PLL circuit 520 may include an oscillator 520 a.

The PLL circuit 520 may be controlled based on an automatic frequency compensation control value.

The amplifiers 510 a, 510 b and 510 c may be controlled based on an automatic gain control value.

Although the PLL circuit 520 and the amplifiers 510 a, 510 b and 510 c are controlled by a second modem 207 included in the central unit 200 in FIG. 6, the PLL circuit 520 and the amplifiers 510 a, 510 b and 510 c may be controlled by the first modem 120 included in the remote unit 100, the processor included in each remote unit 100 or the processor 201 included in the central unit 200.

The central unit 200 may include a second modem 207 and an access point 210.

The second modem 207 may be implemented at L1 (Layer 1, e.g., a physical layer), L2 (Layer 2, e.g., a MAC layer), a radio resource control (RRC) layer, or a non-access stratum (NAS) layer.

The second modem 207 may collectively control the plurality of remote units 100.

The second modem 207 may collectively control the PLL circuit and amplifier of each of the plurality of remote units 100.

The second modem 207 may perform phase locked loop (PLL) control. For example, the second modem 207 may perform phase locked loop control through automatic frequency compensation control.

The second modem 207 may perform automatic gain control.

The second modem 207 may calculate an automatic gain control value.

The second modem 207 may control the amplifier of the RF module 110 based on the automatic gain control value.

For example, the second modem 207 may measure a received signal strength indicator (RSSI) of the RF module 110. The second modem 207 may calculate the automatic gain control value based on the measured RSSI data.

The second modem 207 may perform automatic frequency compensation control.

The second modem 207 may calculate an automatic frequency compensation control value.

The second modem 207 may control the PLL circuit of the RF module 110 based on the automatic frequency compensation control value.

For example, the second modem 207 may perform synchronization of the RF module 110. The second modem 207 may calculate an automatic frequency compensation control value based on the synchronization data.

The second modem 207 may modulate a signal transmitted through the RF module 110.

The second modem 207 may demodulate a signal received through the RF module 110.

The above description is applicable to the access point 210.

Meanwhile, an IF unit may be further included between the RF module 110 and the second modem 207.

The IF unit may be included in the remote unit 100.

For example, the IF unit may be disposed between the RF module 110 and the converter 130, based on signal flow.

For example, the IF unit may be disposed after the converter 130, based on signal flow.

The IF unit may be included in the central unit 200.

The IF unit may be disposed before the processor 201, based on signal flow.

The description of FIG. 2 is applicable to the RF module 110 and the IF unit.

FIGS. 7 to 8 are views referenced to describe a vehicle communication apparatus according to an embodiment of the present invention.

Referring to FIG. 7, each of the plurality of remote units 100 may include an RF module 110, a converter 130 and a processor 180.

The above description is applicable to the RF module 110.

The above description is applicable to the converter 130.

The processor 180 may be referred to as an antenna signal processor or a multiple AGC & AFC controller.

The processor 180 may perform phase locked loop (PLL) control. For example, the processor 180 may perform phase locked loop control through automatic frequency compensation control.

The processor 180 may calculate an automatic gain control value.

The processor 180 may control the amplifier of the RF module 110 based on the automatic gain control value.

The processor 180 may calculate an automatic frequency compensation control value.

The processor 180 may control the PLL circuit of the RF module 110 based on the automatic frequency compensation control value.

The central unit 200 may include a second modem 206 and an access point 210.

The second modem 206 may be implemented at L1 (Layer 1, e.g., a physical layer), L2 (Layer 2, e.g., a MAC layer), a radio resource control (RRC) layer, or a non-access stratum (NAS) layer.

The second modem 206 may measure a received signal strength indicator (RSSI) of the RF module 110. The second modem 206 may provide the measured RSSI data to the processor 201. The processor 201 may calculate an automatic gain control value based on the RSSI data.

The second modem 206 may perform synchronization of the RF module 110. The second modem 206 may provide synchronization data to the processor 201. The processor 201 may calculate an automatic frequency compensation control value based on the synchronization data.

The second modem 206 may modulate a signal transmitted through the RF module 110.

The second modem 206 may demodulate a signal received through the RF module 110.

The above description is applicable to the access point 210.

Meanwhile, an IF unit may be further included between the RF module 110 and the second modem 206.

The IF unit may be included in the remote unit 100.

For example, the IF unit may be disposed between the RF module 110 and the converter 130, based on signal flow.

For example, the IF unit may be disposed between the converter 130 and the processor 180, based on signal flow.

For example, the IF unit may be disposed after the processor 180, based on signal flow.

The IF unit may be included in the central unit 200.

The IF unit may be disposed before the second modem 206, based on signal flow.

The description of FIG. 2 is applicable to the RF module 110 and the IF unit.

Referring to FIG. 8, each of the plurality of remote units 100 may include an RF module 110, a converter 130 and a first processor 190.

The above description is applicable to the RF module 110.

The above description is applicable to the converter 130.

The first processor 190 may calculate an automatic frequency compensation control value.

The first processor 190 may control the PLL circuit of the RF module 110 based on the automatic frequency compensation control value.

The first processor 190 may be referred to as an AFC controller.

The central unit 200 may include a second processor 301, a chain selector 302, and an access point 210.

The second processor 301 may calculate an automatic gain control value.

The second processor 301 may control the amplifier of the RF module 110 based on the automatic gain control value.

The second processor 301 may be referred to as an AGC controller.

The chain selector 320 may select some of a plurality of signals respectively provided to the plurality of remote units, when the number of ports of the second modem is less than the number of remote units.

For example, the chain selector 302 may select the remote units in descending order of the automatic gain control values respectively received from the plurality of remote units 100.

The chain selector 302 may provide the selected signal to the second modem 206.

The description of the second modem 206 in FIG. 7 is applicable to the second modem 206.

Meanwhile, an IF unit may be further included between the RF module 110 and the second modem 206.

The IF unit may be included in the remote unit 100.

For example, the IF unit may be disposed between the RF module 110 and the converter 130, based on signal flow.

For example, the IF unit may be disposed between the converter 130 and the first processor 190, based on signal flow.

For example, the IF unit may be disposed after the first processor 190, based on signal flow.

The IF unit may be included in the central unit 200.

The IF unit may be disposed before the second processor 301, based on signal flow.

The IF unit may be disposed between the second processor 301 and the chain selector 302, based on signal flow.

The IF unit may be disposed between the chain selector 302 and the modem 206, based on signal flow.

The description of FIG. 2 is applicable to the RF module 110 and the IF unit.

FIG. 9 is a view referenced to describe a plurality of array antennas according to an embodiment of the present invention.

The vehicle communication apparatus 10 may include a plurality of array antennas 111 a, 111 b, 111 c, 111 d, 111 e, 111 f and 111 g.

The plurality of array antennas 111 a, 111 b, 111 c, 111 d, 111 e, 111 f and 111 g may be distributed and disposed on the upper end of the vehicle body.

For example, the array antennas may be distributed and attached to at least one of an upper end of a hood, an upper end of a roof, an upper end of a trunk, a front windshield, a rear windshield or an upper end of a side mirror.

By distributing the plurality of array antennas, it is possible to support a high data rate and high quality of service (QoS) like one large array antenna. Furthermore, it is possible to implement a multiple input multiple output (MIMO) system.

According to an example or implementation example of the present invention, in the method of controlling an amplifier (Amp) and a phase locked loop (PLL) on an RU basis as described in FIG. 7, a method of implementing the ADC function of an RX chain in an automatic gain control/automatic frequency compensation control (AGC/AFC) controller block is proposed. FIG. 10 illustrates addition of an AGC/AFC controller block to a remote radio head (RRH) according to an example or implementation example of the present invention. Referring to FIG. 10, the ADC function may be implemented in an AGC/AFC controller block.

According to the structure illustrated in FIG. 10, an analog signal may be transmitted between an RRH and an AGC/AFC controller block through a coaxial cable or the like, which is different from the implementation method described with reference to FIG. 7. Further, it may be easy to implement the example of FIG. 10, compared to the example of FIG. 7 in which cabling is required to receive a high-speed digital signal as an input signal of the AGC/AFC controller. Further, since an ADC block is located inside the AGC/AFC controller block, the analog signal passing through a low pass filter may be input to the AGC/AFC controller block. When the ADC block is located inside the AGC/AFC controller block, user equipment (UE) implementation cost may be lowered compared to a digital interface, in spite of attenuation loss.

Signaling for supporting an in-vehicle distributed antenna system between a base station (BS) and a vehicle UE may be considered. Preferably, the distributed antenna vehicle UE may be introduced to the BS in a “UE-type transparent” manner. In other words, it may be favorable to design a system such that a BS performs a unified operation without the need for determining whether an individual vehicle UE is a centralized antenna vehicle UE or a distributed antenna vehicle UE. Therefore, signaling between the BS and the vehicle UE, which is required additionally for the in-vehicle distributed antenna system, may be performed by RF switching based on an operation of an RU selector included in a CU. For example, the vehicle UE may i) perform RU selection at the CR based on information about the traveling path and position of a vehicle, and received signal quality (e.g., RSSI) measurement(s) of individual RU(s), and ii) request the BS to change a modulation and coding scheme (MCS) or transmission power based on the above information, for improving communication performance.

According to an example or implementation example of the present invention, when reporting channel state information (CSI) based on the received signal qualities (e.g., RSSIs) of the individual RUs to the BS, the CU of the distributed antenna vehicle UE may report i) a plurality of channel quality indicators (CQIs) for the respective RUs and ii) an RU index selected by an RU selector. Further, when an RU selected by the RU selector of the CU has been changed or is expected to be changed, the vehicle UE may aperiodically RU selection/change information to the BS on a random access channel (RACH) and/or a sounding reference signal (SRS), to request change of an MCS accordingly.

More specifically, the distributed antenna vehicle UE may request allocation of an MCS suitable for the vehicle UE to the BS by reporting the plurality of CQIs for the respective RUs and the RU index selected by the RU selector (or chain selector) of the distributed antenna vehicle in the CSI report. For example, a distributed antenna vehicle UE with two RUs may form a CQI set including i) a CQI for each RU and ii) the index (e.g., 1 or 2) of an RU selected by an RU selector, such as {CQI1, CQI2, selected RU index}. However, the CQI set is not necessarily reported at the same CSI reporting timing. That is, a CSI feedback field value may be set to a combination of a plurality of CQIs+an RU index, not a single CQI report per UE. The individual values may be reported at the same or different reporting timings and/or in the same or different reporting periods to the BS.

Further, i) when the RU selected by the RU selector of the distributed antenna vehicle UE has been changed or ii) when there is no change in the RU at present but it is expected that the RU will be changed soon based on the received quality measurement of each individual RU, the distributed antenna vehicle UE may explicitly indicate RU index information to be changed to the BS on a physical random access channel (PRACH) or an SRS irrespective of its CSI reporting period, or may indicate only whether the RU has been changed to the BS by a specific indicator (e.g., a 1-bit indicator). The RU index information and the indicator indicating whether the RU has been changed may be represented as a sequence or bit added to the RACH and/or the SRS.

When the UE provides CQIs and RU selection information to the BS as described above, the BS may determine an MCS based on a specific reported CQI. According to another example or implementation example of the present invention, the vehicle UE may transmit an MCS change request to the BS by reporting the CQI of an RU with the lowest channel gain, selected by the chain selector, or may calculate a single CQI based on the average received power of a plurality of RUs selected by the chain selector and report the calculated single CQI to the BS. In this case, the BS does not need to operate by identifying whether the vehicle UE is a distributed antenna UE or a centralized antenna UE, and various methods may be considered according to a UE implementation method.

According to an example or implementation example of the present invention, when an RU selected by the RU selector of the CU has been changed or the selected RU is expected to be changed, the distributed antenna vehicle UE may transmit a power headroom report (PHR) to the BS by uplink communication according to the RU selected determination.

When the RU selected by the RU selector of the distributed antenna vehicle UE has been changed or when there is no change of the RU at present but the RU is expected to be changed based on the received quality measurements of individual RUs, obtained so far, the distributed antenna vehicle UE may request reallocation of resources and transmission power to the BS by transmitting a PHR to the BS. In an exemplary proposal, the CU may transmit the PHR based on an RU having the lowest channel gain, selected by the RU selector (or chain selector) or may calculate the average PHR value of a plurality of selected RUs and transmit the calculated average PHR value to the BS. Therefore, communication performance may be increased.

When a PLL is disposed in each RU in the distributed antenna vehicle UE, the RUs may have different time offset values and/or frequency offset values generated from their antenna ports. For example, because different time delays are involved in transmission from the individual RUs to the CU due to different distances between the RUs and the CU, interfaces between the RUs and the CU, and so on, a timing error may occur between the RUs. Moreover, signals generated from PLL implementation in each individual RU are input to the CU. Therefore, the CU has different values for antenna port groups included in the respective RUs, and thus a frequency error may easily occur between antenna ports (or antenna groups) even within a single UE. The distributed antenna vehicle UE may indicate a capability regarding a time error and/or a frequency error between antenna ports to the BS to increase UL and DL data transmission performance of the UE.

According to an example or implementation example of the present disclosure, the distributed antenna vehicle may signal a capability regarding a time error and/or a frequency error between its antenna ports grouped according to a plurality of RUs to the BS, so that the BS may perform precoding suitable for the situation of the UE or select a transmission mode suitable for the situation of the UE.

As far as the BS knows that different time offsets and/or frequency offsets are generated for antenna port groups included in the respective RUs according to the report of the vehicle UE, the BS may improve performance by applying precoding suitable for the UE situation or indicating transmission mode switching.

For example, in downlink communication, when the BS receives, from the UE, signaling indicating that the UE is a distributed antenna vehicle UE to which a frequency error has occurred between RUs, the BS may perform transmission mode switching to perform open-loop transmission based on the signaling. In another example, in uplink communication, the BS may receive, from the UE, signaling indicating that the vehicle is a distributed antenna UE having a frequency error, and apply a diversity scheme to antennas having similar frequency offsets (e.g., an antenna group belonging to the same RU) based on SRS measurements through antenna port virtualization. Which scheme or precoding is to be applied to improve communication performance may be determined in, but not limited to, various methods according to the above-described signaling from the vehicle UE depending on the implementation of the BS.

In new RAT (NR), the introduction of a 2-step transceiver which converts a baseband signal to an intermediate frequency (IF) signal and then to a high-frequency band signal, instead of a transceiver for directly converting a baseband signal to a high-frequency band signal, is considered in a discussion of communication using a high frequency band such as a millimeter wave (mmWave) band. For example, for communication using the mmWave frequency band (e.g., 28 GHz), a first transceiver may upconvert a baseband signal to a signal in an IF band (e.g., 8-10 GHz), and a second transceiver may finally upconvert the signal in the IF band (e.g., 8-10 GHz) to a signal in an mmWave band (e.g., 28 GHz).

Referring to FIG. 11, an IF function block may be added between an RFIC and a modem. The RFIC may perform upconversion from an IF to an mmWave band (e.g., from 8 to 10 GHz to 28 GHz) (or vice versa). The IF block may perform upconversion from a baseband to an IF band (e.g., 8 to 10 GHz) (or vice versa). For this purpose, the RFIC may further include an IF local oscillator and a PLL for IF, for downconverting an RF signal to an IF signal (or vice versa). Various 2-step conversion methods may be applied to a transceiver.

The above-described conversion to an IF band may be applied throughout general communication irrespective of vehicle communication or antenna distribution. That is, when an implementation reference model related to distribution of function blocks between an RU and a CU is considered, a reference model having a 3-step function block of RFIC/modem/AP as illustrated in FIG. 12 may be applied in a similar manner to a 4-step function block of RFIC/IF/modem/AP in which IF band conversion is additionally considered, as illustrated in FIG. 11. That is, function block distribution between an RU and a CU may be performed in various combinations as follows.

-   -   i) {RU:antenna}+{CU:RFIC+IF+Modem+AP},     -   ii) {RU:antenna, RFIC}+{CUIF+Modem+AP},     -   iii) {RU:antenna, RFIC, IF}+{CU:Modem+AP},     -   iv) {RU:antenna, RFIC+IF+Modem(partial)}+{CU: Modem(partial)+AP}

However, considering that cabling loss caused by a distance during analog signal transmission between an RU and a CU is more serious in a high frequency area, ii) a {RU:antenna, RFIC}+{CU:IF+Modem+AP} combination in which RU-CU cabling may be considered by partially downconverting a frequency to an IF band may be preferred to a {RU:antenna}+{CU:RFIC+IF+Modem+AP} combination in which an RF analog signal should be transmitted between an RU and a CU by a cable.

According to an example or implementation example of the present invention, a vehicle communication apparatus may include i) a plurality of remote units (RUs) configured to transmit and receive signals through a mobile communication network, and ii) a central unit (CU) coupled to the plurality of RUs and configured to provide signals received through the plurality of RUs to a device located in a vehicle. Each of the plurality of RUs may include a radio frequency (RF) module and a modem configured to control the RF module. Particularly, the modem may include an analog-to-digital converter (ADC) configured to convert an analog signal output from the RF module to a digital signal.

The RF module may include at least one phase locked loop (PLL) control circuit and at least one amplifier (Amp).

The modem may control i) the Amp based on a calculated automatic gain control (AGC) value, and ii) the PLL control circuit based on a calculated automatic frequency compensation control (AFC) value. The CU may further include a chain selector configured to select a part of a plurality of signals received through the plurality of RUs, respectively.

The CU may transmit channel state information (CSI) to a base station (BS) through the RF module. Particularly, the CSI may include i) a channel quality indicator (CQI) for each of the plurality of RUs, and ii) an index of a specific RU selected from among the plurality of RUs by the chain selector.

The CU may identify change of a first RU selected by the chain selector to a second RU, and transmit a power headroom report (PHR) including a request for reallocation of resources and transmission power to the BS through the RF module.

The CU may report information about a timing offset difference and a frequency offset difference between the plurality of RUs to the BS through the RF module.

The CU may further include an intermediate frequency (IF) module configured to perform conversion between frequency bands. Particularly, the IF module may primarily convert a baseband signal to a signal in an IF band, and the RF module may secondarily convert the signal in the IF band to a signal in a millimeter wave (mmWave) band.

The IF band may include at least part of a band of 8 GHz to 10 GHz.

The device may include at least a mobile terminal of a passenger in the vehicle or a user interface device provided in the vehicle.

The present invention may be implemented as code that can be written to a computer-readable recording medium and can thus be read by a computer. The computer-readable recording medium may be any type of recording device in which data can be stored in a computer-readable manner. Examples of the computer-readable recording medium include a hard disk drive (HDD), a solid state drive (SSD), a silicon disk drive (SDD), a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, optical data storage, and a carrier wave (e.g., data transmission over the Internet). In addition, the computer may include a processor or a controller. The above exemplary embodiments are therefore to be construed in all aspects as illustrative and not restrictive. The scope of the invention should be determined by the appended claims and their legal equivalents, not by the above description, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein. 

The invention claimed is:
 1. A vehicle communication apparatus comprising: a plurality of remote units (RUs) configured to transmit and receive signals through a mobile communication network; and a central unit (CU) coupled to the plurality of RUs, and configured to provide signals received through the plurality of RUs to a device located in a vehicle, wherein each of the plurality of RUs includes: a radio frequency (RF) module that includes at least one phase locked loop (PLL) control circuit and at least one amplifier (Amp), and a modem that includes an analog-to-digital converter (ADC) configured to convert an analog signal output from the RF module to a digital signal and that is configured to control the RF module, the modem being configured to control the at least one Amp based on a calculated automatic gain control (AGC) value, and to control the at least one PLL control circuit based on a calculated automatic frequency compensation control (AFC) value.
 2. The vehicle communication apparatus according to claim 1, wherein the CU further includes a chain selector configured to select a part of a plurality of signals received through the plurality of RUs, respectively.
 3. The vehicle communication apparatus according to claim 2, wherein the CU transmits channel state information (CSI) to a base station (BS) through the RF module, and wherein the CSI includes i) a channel quality indicator (CQI) for each of the plurality of RUs, and ii) an index of a specific RU selected from among the plurality of RUs by the chain selector.
 4. The vehicle communication apparatus according to claim 2, wherein the CU identifies change of a first RU selected by the chain selector to a second RU, and transmits a power headroom report (PHR) including a request for reallocation of resources and transmission power to a base station (BS) through the RF module.
 5. The vehicle communication apparatus according to claim 1, wherein the CU reports information about a timing offset difference and a frequency offset difference between the plurality of RUs to a base station (BS) through the RF module.
 6. The vehicle communication apparatus according to claim 1, wherein the CU further includes an intermediate frequency (IF) module configured to perform conversion between frequency bands, and wherein the IF module primarily converts a baseband signal to a signal in an IF band, and the RF module secondarily converts the signal in the IF band to a signal in a millimeter wave (mmWave) band.
 7. The vehicle communication apparatus according to claim 6, wherein the IF band includes at least part of a band of 8 GHz to 10 GHz.
 8. The vehicle communication apparatus according to claim 1, wherein the device includes at least a mobile terminal of a passenger in the vehicle or a user interface device provided in the vehicle.
 9. A method of controlling a vehicle communication apparatus, the method comprising: receiving and processing signals through a plurality of remote units (RUs); and providing the processed signals to a device located in a vehicle through a central unit (CU) coupled to the plurality of RUs, wherein the receiving and processing of signals comprises: converting an analog signal output from a radio frequency (RF) module to a digital signal through an analog to digital converter (ADC) included in a modem, the RF module including at least one phase locked loop (PLL) control circuit and at least one amplifier (Amp), controlling the at least one Amp based on a calculated automatic gain control (AGC) value, and controlling the at least one PLL control circuit based on a calculated automatic frequency compensation control (AFC) value.
 10. The method according to claim 9, further comprising selecting a part of a plurality of signals received through the plurality of RUs through a chain selector.
 11. The method according to claim 10, further comprising transmitting channel state information (CSI) to a base station (B S) through the RF module, wherein the CSI includes i) a channel quality indicator (CQI) for each of the plurality of RUs, and ii) an index of a specific RU selected from among the plurality of RUs by the chain selector.
 12. The method according to claim 10, further comprising: identifying change of a first RU selected by the chain selector to a second RU; and transmitting a power headroom report (PHR) including a request for reallocation of resources and transmission power to a base station (BS) through the RF module.
 13. The method according to claim 9, further comprising: primarily converting a baseband signal to a signal in an intermediate frequency (IF) band through an IF module; and secondarily converting the signal in the IF band to a signal in a millimeter wave (mmWave) band through the RF module. 